The paper focuses on "toxic substances and disease causation," and proposes the following "six working principles that may render 'causation' a less mysterious element to understand and apply":

Causation in science is not synonymous with causation in law, but the gap has closed.

Proof of general causation requires, at a minimum, reliable epidemiology and a statistically significant estimated relative risk of more than 2.0.

Proving causation does not end with the general causation inquiry. Proof of specific causation is absolutely essential before any causal conclusions can be drawn.

Risk assessment is the best tool available to answer questions of causation.

Although risk assessment is the best tool available, regulatory rules for implementing risk assessments should not be used, and too often are abused.

Where there are multiple exposure sources for the same toxin, a more principled, objectively reliable methodology should be used to answer questions of causation. Concepts such as “substantial contributing” cause should be jettisoned.